The right camera settings will make a HUGE difference in the quality of footage you capture when you are filming mountain biking POV footage. I have been using the Osmo Action 3 and the Osmo Action 4 for mountain biking in a variety of situations, and I've learned a few powerful lessons on what settings to use in order to get the smoothest looking video content.
I'm still learning so I'm definitely not a seasoned expert, but I also think that the camera technology is good and a few quick settings changes could be the difference between great looking video, and a shaky and distorted view of the trail.